DESCRIPTION (adapted from the Abstract); This research deals with social structures and processes that affect the sexual transmission of disease, including HIV. The social aspects of risky sexual behavior the Principal Investigator and his associates will address include the relationship between social institutions, social lifestyle patterns and persons at risk, the contribution of early social learning experiences to risky sexual behavior over the life course, network processes by which diseases are transmitted sexually, sexual scripts that guide partner choice and sexual practices, and the "sexual marketplace" in which preferences and opportunities come together to produce particular sorts of relationships-- some more risky than others. Using nationally representative data on the distribution of sexual behavior and attitudes (the National Health and Social Life Survey, or NHSLS), detailed data from the Chicago metropolitan area about partner characteristics, networks and neighborhoods (the Chicago Health and Social Life Survey, or CHSLS), and drawing on related textual data drawn from open-ended interviews with representatives of the legal, health, religious and social service institutional spheres in each of four Chicago neighborhoods where representative surveys of residents were also conducted, these researchers will seek to illuminate the social underpinnings of risky sexual behavior. Using network models, logistic regression and latent class analysis, they will elaborate efficient methods of identifying persons at risk of contracting sexually-transmitted infections and of identifying key bridge persons who are most efficient at transmitting infection to wide segments of the population. The researchers will then link these individuals to the underlying social statuses and processes that organize their risky behavior: their early sexual learning experience, their social networks, their partnering opportunity structures, and the cultural scenarios and interpersonal scripts that give meaning to their behavior. Finally, the researchers will use the text-base materials from interviews with institutional actors to describe how persons at risk interact with social religious, legal and health organizations and how their behavior and related outcomes are viewed and treated by these various institutions. This research should facilitate the identification of classes of persons to target for intervention and inform the process of crafting effective venues and messages for various at-risk groups.